Airplane carburetor



Feb. 11, 1930. F. c. MocK 1,746,358

AIRPLANE CARBURETOR Original Filed Jan. 16, 1924 3 Sheets-Sheet l Feb. 11,1930. F C; MOCK 1,746,358

AIRPLANE CARBURETOR Original Filed Jan. 16, 1924 3 Sheets-Sheet 2 Jg@ t :ggg-Z Q v !g v will; y 7%@ f/" i i 273 17g je@ Feb. 1l, 1930. F; C, MQCK 1,746,358

l AIRPLANE CARBURETOR Original Filed Jan. 16, 1924 3 Sheets-Sheet 3 Patented lll, 1933@ 'llladll' C. MUCH, @F CHCAGO, ELLINOS, SSG-NGB TG STRGMBERG MOTOR DEVEES CE., lIl" CHECAGQ, HMNOIS, CORPORATION O1? f uLl'OIS LANE CMIB'URETQR @riginal application :filed January 16, 19124, Serial ito..686,47. Divided and this application med March 16,

1926. Serial lilo. 95,516'.

lli/ly invention relates yto carburetors, more especially to airplane carburetors, and the ob- 5 at ditl'erent altitudes. 'lhis application is a division oi' my co-pending application, Case 29, Serial No. 686,474, tiled January 16, 1924, which has matured into Patent No. 1,600,008, dated September 14, 1926.

rl`he various features of my invention are incorporated in the structure disclosed on the drawings,in which:

Fig. 1 is a plan view of a single barrel carburetor;

Fig. 2 is a verticalsectional view takenap proximately on line 2-2 of Fig. 1; and

l? ig. 3 isa transverse sectional view taken on line 3 3 of lTig. 1. l have shown a single barrel carburetor l have illustrated an arrangement of alti? tude control which has equal applicability tol single or double barreled carburetors. rllhis altitude control is edected by shunting an additional volume of air around the Venturi tube 150 at high altitude to give the desired Yincrease of capacity tor a greater air tlow. Such a shunting passageway is illustrated at 165 in l? ig. 3, the lower end of this passage' way drawing air from the carburetor air intake 155, and the upper end discharging into a substantially annular chamber 166 opening into the carburetor barrel in the upper casing section. A throttle valve 167 on a throttle shatt168 controls the llow of supplementary air through this passageway. @n the outer end of the throttle shaft 163 is an o erating comprising the carburetor barrel 1119 withinl arm 163'.. trom which extends a suita le operating connection to an actuating member in t fthe pilots cockpit. ject is to provide improved means for eiitil ciently controlling the operation when Vdying l have provided an improved` arrangementof back suction lcontrol which co-operates` with the function of shunting additional air through the passageway 165, to the end of starting and interrupting and graduating a suction edective in the iloat chamber above the fuel level in accordance with changes of positionv of the supplementary air throttle 60 167. back suction channel 169 is extended lengthwise of the outer wall of the shunting passageway 165, and this bach suction channel is placed in communication with this shunting passageway through `a port 171 55 which opens into the passaofeway`165 below the valve 167. As shown inligs. 2 and 3, the upper end of the channel or duct 169 is eX- tended across to the top ora the oat chamber 152, where it connnunicateswith'the upper area of the float chamber through a port 172. A spider or ring 173 is threaded into the top of the oat chamber to support a ball check valve 174, which'checlr valve is adapted to close the port 172 when the carburetor is inya verted. Thelower endl of the duct 169 is extended laterally into the lower of the i'doat chamber through the horizontal passageway 175, lWhen the supplementary air1 valve 167 is closed the pressure eective on the air 30 entrance side of the carbureting chamber will be transmitted through port 171, duct 169 and port 172 into the upper area of the oat charn- Yber. llas the supplementary air valve 167 is opened" a gradually increasing suction is created in the shunting passageway 165, whichsuction is transmitted through these saine ports and air ductto the upper area of the float chamber. When the carburetor is inverted, asin upside down flying, or in other maneuvers, or when the craft is stalling in a loop, the ball ycheclr 17 l drops onto the seat 172, thereby closing this end ot the back suction duct 169 against outflow oi? fuel, alter which any back' suction transm'tted to the a5 `float chamber occurs through the other end ot the duct 169 and through the lateral passageway 175. llor supplyingiuel tothe carburet- ,ing chamberdurin@ this upside down dying, a nozzle' 177 may be screwed into the side wall of the float chamber, to extend through an aperture in the Venturi tube 150, and discharge into this tube at a level considerably above the level of the main nozzle 151. When the carburetor is inverted this nozzle 177 is submerged and supplies a normal running mixture. During such time, the main nozzle transmits a certain degree of back suction to the float chamber above the fuel level; and conversely, when the carburetor is upright the nozzle 177 transmits a certain back suction to the float chamber above thefuel level.

The range of altitude control eifected by by-passing air through the passageway is limited by the necessary proportions of the parts. The back-suction altitude control ef` fected through the channel 169 extends the range of control considerably beyond that aorded by the-by-pass 165. The one control merges into the other gradually, this resulting from the fact that the suction prevailing in proximity to the port 171 is increased with the opening of the valve 167, and this increasing suction is in turn transmitted to the float chamber.

Having described my invention, I claim as follows:

1. In a carburetor, the combinationj of a mixture passageway, a Venturi tube in said passageway, a fuel inlet opening into said Venturi tube, a by-pass in shunt of said Venturi tube, a valve in said by-pass, a float chamber supplying said fuel inlet, and a back` suction channel communicating with Said float chamber and opening into said by-pass on the atmospheric side ofsaid valve.

2. In a carburetor, the combination of a mixture passageway having an air inlet and a throttle valve controlled mixture outlet, a fuel inlet between said air inlet and mixture outlet, a float chamber supplying said fuel inlet, a by-pass around said fuel inlet connecting said air inlet directly with said mixture passageway, a back suction channel communicating with said float chamber and with said by-pass to be subjected to the suction effect in said mixture passageway when said by-pass is opened, and a valve for controllingI the passageway through said by-pass andfror disconnecting said channel from said mixture passageway.

In witness whereof, I hereunto subscribe my name this 9th day of March, 1926.

FRANK C. MOCK. 

